Lumber separator

ABSTRACT

A lumber separator is described for receiving, separating and re-routing a vertical stack of boards, particularly such stacks formed by horizontal resawing operations of a lumber mill. The separator receives an individual stack from a longitudinal input conveyor on a relatively horizontal table. A plurality of transverse conveyor chains move the stack laterally over the table, onto the arms of a removable support means, and against an abutment with sufficient velocity to dislodge the top stack member. The bottom board is dropped as the arms are retracted, onto a bottom board conveyor.

O Unlted States Patent 1 [111 3,782,540 Mosely Jan. 1, 1974 LUMBER SEPARATOR [75] Inventor: Donald E. Mosely, Spokane, Wash. Pr'mary ExammerRlchard Schacher Attorney-Greek Wells et a1. [73] Assignee: Bitco, lnc., Spokane, Wash. 22 Filed: Sept, 28, 1972 [57] ABSTRACT A lumber separator is described for receiving, separat- [211 Appl' 293447 ing and re-routing a vertical stack of boards, particularly such stacks formed by horizontal resawing opera- [52] US, Cl U 209/73, 209/74 R, 209/32, tions of a lumber mill. The separator receives an indi- 209/90 vidual stack from a longitudinal input conveyor on a [51] Int. Cl. B07c 1/10 relatively horizontal a A p a ity f t ans rse [58 Field of Search 209/73, 74 R, 82, conveyor chains move the stack laterally over the 209/90; 144/312; 214/85 R ble, onto the arms of a removable support means, and

. against an abutment with sufficient velocity to dis- [561 Refere Cit d lodge the top stack member. The bottom board is UNITED STATES PATENTS dropped as the arms are retracted, onto a bottom 2,876,815 3 1959 Rogers 209/82 x board Convey 3,516,539 6/1970 Gulstrom 209/74 R 5 Claims, 8 Drawing Figures 49 0 :3 r I (7 -q ai Z0 57 0o 00 ".?3

' u o 6 d and1 5 a 47 '22 r7 5? 55 5a FIG1 PATENTEDJAN 1 i974 sum 1 or 3 PATENTEDJAN, H 3,782,540

' sum 3 or 3 Q FIG 5 50 LUMBER SEPARATOR BACKGROUND OF THE INVENTION Modern lumber mills often include a horizontal bandsawor resaw which is used for cutting cants, or squared off logs, lengthwise into usable dimension lumber. As the cant is directed past the resaw station, a board is cut from the bottom of the cant. The cut bottom board and the remainder of the cant are directed downstream with the remainder superimposed on the bottom board. This requires a separation operation to remove the cant remainder from the bottom board and direct the cant back to the resaw station. This step has previously involved a millworker who would separate the bottom board and the cant remainder and direct the cant back to the resaw station for further resawing or to other facilities for other purposes according to its size. Such manual effort is dangerous to the millworker as well as time consuming and expensive.

A machine utilized to alleviate the above problem to a limited degree is describedin the Lunden et al U. S. Pat. No. 3,104,005. The patent describes a lumber separator which utilizes lateral conveyors for moving the vertically stacked cant and the bottom board into a fixed abutment. The momentum of the cant causes it to pass over the abutment and onto a resaw return conveyor. The bottom board then is directed longitudinally for further processing. 7

The primary difficulty with the above machine is its relatively slow operating speed, since the bottom board must be moved lengthwise away from the separation station before another resawed cant may be received by the lateral conveyors.

It is therefore a primary object of my invention to provide a more efficient lumber separator that includes means for quickly removing the sized board from the lateral conveyor, thereby increasing operating speed over the machine cited above.

An additional object of my invention is to provide such a lumber separator that, because of its less complicated construction, is relatively inexpensive.

A further object is to provide such a lumber separator that includes control means which enables selective placement of the cant according to its size.

These and further objects and advantages will become evident upon reading the following description which, when taken with the attached drawings, describe a preferred form of my invention.

A BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the separator adjacent a feed conveyor which is illustrated in dashed lines;

FIG. 2 is a sectioned elevational view taken along line 2-2 in FIG. 1-,

FIG. 3 is a fragmentary sectioned elevational view taken along line 3-3 in FIG. I;

FIG. 4 is a fragmentary sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a diagrammatic view illustrating relative operative positions of the separator when the cant and tinished usable board are of equal dimension;

FIG. 6 is a diagrammatic view similar to FIG. 5 only illustrating the operative positions of the separator when the cant is of greater dimension than the usable board;

FIG. 7 is a diagrammatic view illustrating the operative positions of the abutment means when the cant is of smaller dimension than the usable board; and

FIG. 8 is a diagrammatic view illustrating the removal of a usable board from the lateral conveyor.

DESCRIPTION OF A PREFERRED EMBODIMENT Horizontally oriented bandsaws or resaws are often utilized in the present lumber industry for progressively cutting squared off logs or cants into dimension lumber. In the cutting operation, individual cants are fed lengthwise into the horizontal cutting flight of the saw. The resulting cut leaves the cant in two vertically stacked longitudinal pieces, the remainder of the cant being superimposed over a dimensioned bottom board. The stack is moved from the resaw along a longitudinal path to a separating station, usually immediately down stream of the resaw, where the dimensioned board and remaining cant are separated and rerouted for further processing. The thickness of the remaining cant determines one of three possible succeeding routing operations. First, if the remaining cant is equal in thickness to the board below, it is directed, along with the bottom board, for further processing. If the cant is larger than the previously cut dimensioned board, it is separated from the board and sent back to the resaw for an additional cut. Finally, if the remaining cant is smaller than the dimensioned board, it is separated from the board and routed to a chipper or other processing equipment.

The lumber separator described below and illustrated in the attached drawings'is designed to selectively separate the cant from a dimensioned board and direct each onward for further processing.

Referring now to the drawings, there is shown in FIG. 1, a section of an input or feed conveyor 12 adjacent the separator shown at 16 adjacent the separating station. Conveyor 12 is utilized to receive individual stacks after the resaw operation. and move them onto separator I6 in a longitudinal path.

It should be noted, that the separator 16 illustrated in the drawings is designed to receive one cant at a time. A pair of separators I6 could however be easily arranged as shown in U. S. Pat. No. 3,104,005 to receive two cants in parallel at a time.

As may be seen in FIG. 2, the resawing operation leaves a cant I0 superimposed on a board Ill of a desired thickness forming a stack. This vertical stack is moved longitudinally and deposited, by conveyor 12, onto a planar table 14 of separator 16. Conveyor 12, illustrated in dotted lines in FIG. I is positioned elevationally above table M to facilitate operative engagement of a stack until it rests entirely on table 14.

Table 14 is supported in a relatively horizontal orientation by a supporting framework 17. Separator 16 includes a lateral conveying means 18 for moving the stack laterally across table 14. Conveying means 18 includes a series of laterally directed endless chains 20 for receiving the stack from the infeed conveyor 12 and moving the stack laterally in a transverse path.

A drive means 19 is operatively connected to a drive shaft 23 extending between the chains 20. Each chain 20 is supported between a drive sprocket 24 affixed to shaft 23 and an idler 25. The upper flights of chains 20 are slidably held within recessed guides in table 14 (FIG. 4) to allow movement of the stack longitudinally on the table surface. Longitudinally aligned lugs 22 (FIG. 2) protrude above the surface of table 14 along the upper flights of chains for selectively engaging a stack to move it laterally over table R4 to a removable support means 23.

Support means 28 includes a plurality of retractable arms 30 movably mounted 'to table 14 for translational reciprocating movement parallel to the transverse path of a stack on chains 20. Arms 30 are movably supported by rollers 34 within opposed lateral guide channels 33 (FIG. 4) mounted to the underside of table 14.

A second drive means 35 (MG. 3) is operatively connected to arms 30 to move them in unison between a retracted position and extended position as shown in FIG. 3 in solid and dashed lines respectively. The drive means 35 includes pneumatic or hydraulic cylinders 36 mounted to frame 17 with their piston rods 37 affixed to the inner end of selected arms 30. A gear rack 38 is fixed to the bottom of each arm 30 meshing with a pinion 40 affixed to a common shaft 4i (FlG. 4). Therefore, as cylinders 36 are activated to retract or extend, the attached arms and associated racks are retracted or extended respectively. Linear movement of the racks 38 is transferred to rotational movement of shaft 41. This rotational movement of the shaft 41 is transferred to linear movement of the remaining arms 30.

Arms 30 are extended or retracted to either bridge or open a space between ends of conveyor chains 20 and an opposed vertical fixed abutment 44. Chains 20 are driven at a velocity sufficient to slide a stack across the smooth upper surfaces of arms 36D and into abutment 44 with sufficient force to separate the cant from the board. The abutment 44 projects above the arms 30 at a distance less than the thickness of the dimensioned bottom board to facilitate such separation.

As previously stated, the thickness FIG. the remaining cant is the criterion used to determine whether the cant is to be returned to the resaw, moved along with the dimensioned board, or routed for other processing. If the thickness of the cant is greater than the dimensioned board, abutment 44 may be utilized as described above to separate the cant and board. Such a separation is illustrated graphically in Fig. a. After striking abutment 44, the dimensioned board remains stationary on arms 30 while the momentum carries the cant over the abutment 44 and onto an inclined track of rollers 50. The cant moves by gravity down the rollers 50 to a longitudinal resaw return conveyor 57 which moves it back to the resaw for another cut. The dimensioned board is dropped immediately after separation from the cant onto either a second longitudinal conveyor 58 or an auxiliary conveyor 63 as the arms 3t) are retracted (FIG. 8). Conveyors 58 and 63 are located elevationally below arms 30 to receive boards therefrom and to move them longitudinally to another operational station. A deflector plate 60 is pivotably positioned intermediate conveyors 58 and 63 and may be selectively pivoted by cylinders 61 to direct a falling board onto either conveyor 58 or conveyor 63.

The reciprocating movement of arms 30 is an important feature of my invention in that they facilitate quick removal of a dimensioned board from the trasverse path of the next successive stack. The top surfaces of arms 3th are located elevationally lower than table 14 so when they are retracted, the stationary table serves to abut and slide the board off the arms.

The inclined roller tracks 50 are mounted on a frame 47 that is supported for pivotal movement about the horizontal axis of an elongated shaft 48. The frame 47 is pivoted to various orientations by a cylinder 52 (FIG. 2). The piston rod 55 of cylinder 52 is connected to an arm section 56 of frame 47 while the cylinder body is held stationary on separator frame 17. Full retraction of cylinder 52 brings the frame 47 to the normal down position shown in FIGS. 2 and 6. Partial extension of the cylinder 52 swings the free end of the frame 47 above the top of abutment 44 as illustrated in FIG. 5. Full extension of cylinder 52 swings the free end of frame 47 to the elevated position illustrated in FIG. 7.

The three selective elevational positions of frame 47 provide means for selective placement of the cant with respect to its thickness. The first, normal position allows the cant to move by gravity onto conveyor 57 as previously described.

In the partially elevated position 50a, the free end of track frame 47 presents an abutment surface 49 (FIG. 5) aligned with and at an elevation slightly higher than the fixed abutment 44. This position is utilized when the cant and dimensioned board are the same size to halt lateral movement of both boards. Arms 30 may at this position be retracted to drop both boards onto conveyors 58 or 63. h

At the full elevation position (FIG. 7) abutments 49 and 44 are spaced apart a distance sufficient to allow passage of the cant therebetween. A deflector surface 64 on roller frame 47 and a curved guide surface 65 on fixed abutment 44 serve to direct the cant downwardly and away from conveyors 57, 58 and 63. As may be seen in FIG. 7, the full elevation position is utilized when the cant is of less thickness than the dimensioned board.

The three selective positions of roller frame 47 may be controlled automatically as the cant and board leave the resaw by conventional switching means or may also be controlled by the resaw operator.

It may become evident that various changes may be made from the above description and attached drawings and therefore only the following claims are intended to define this invention.

What I claim is:

l. A device for separating a bottom board having a desired thickness from a vertical stack having one or more upper boards superimposed on the bottom board, comprising:

a longitudinal conveyor means for moving the stack of boards lengthwise in a longitudinal path to a separating station;

a lateral conveying means for receiving the stack of boards at the separating station and laterally moving the stack of boards in a transverse path;

a removable support means along the transverse path for receiving the laterally moving stack of boards from the lateral conveyor and selectively slidably supporting the laterally moving stack at a preset elevation in said transverse path;

abutment means adjacent the removable support means having a surface projecting into the transverse path terminating at a height above the preset elevation less than the desired thickness of the bottom board to stop the lateral movement of the bottom board while supported on the removable support means;

a first drive means operatively connected to the lateral conveying means for propelling the stack of boards in the transverse path toward the abutment with a velocity sufficient to cause the upper boards of the stack to slide off the bottom board and over the abutment surface when the bottom board comes to rest against the abutment surface;

a second drive means operatively connected to the removable support means for removing support of 5 the bottom board to allow the bottom board to fall by gravity onto a bottom board conveyor for movement from the separating station.

2. The board separating device as defined in claim 1 wherein the removable support means includes a plurality of arms reciprocally mounted for generally horizontal movement between an extended position to receive the stack from the lateral conveying means and to slidably support the laterally moving stack and retracted position to permit the bottom board to fall by gravity to the bottom board conveyor.

3. The board separating device as defined in claim 2 wherein the lateral conveying means includes a plurality of spaced endless chains having an upper flight for receiving the stack, moving the stack in the transverse path to a forward end of the upper flight opposing and spaced from the abutment surface and discharging the stack onto the arms when the arms are in the extended position and wherein said arms are positioned between the endless chains and project from the forward end of the upper flight to the abutment surface when the arms are in the extended position.

4. The board separating device as defined in claim 2 wherein the second drive means includes:

a common drive shaft extending transversely between the parallel arms;

a plurality of rack gears affixed to the arms;

a plurality of pinion gears affixed on the shaft in engagement with the rack gears;

means operatively connected to the driveshaft for alternately rotating the shaft in opposite angular directions to move the arms between the extended position and the retracted position.

5. The board separating device as defined in claim 1 further comprising a second bottom board conveyor positioned alongside the first bottom board conveyor and a deflector means intermediate the lateral path and the bottom board conveyors for selective directing the bottom board as it falls to one or the other bottom board conveyors. 

1. A device for separating a bottom board having a desired thickness from a vertical stack having one or more upper boards superimposed on the bottom board, comprising: a longitudinal conveyor means for moving the stack of boards lengthwise in a longitudinal path to a separating station; a lateral conveying means for receiving the stack of boards at the separating station and laterally moving the stack of boards in a transverse path; a removable support means along the transverse path for receiving the laterally moving stack of boards from the lateral conveyor and selectively slidably supporting the laterally moving stack at a preset elevation in said transverse path; abutment means adjacent the removable support means having a surface projecting into the transverse path terminating at a height above the preset elevation less than the desired thickness of the bottom board to stop the lateral movement of the bottom board while supported on the removable support means; a first drive means operatively connected to the lateral conveying means for propelling the stack of boards in the transverse path toward the abutment with a velocity sufficient to cause the upper boards of the stack to slide off the bottom board and over the abutment surface when the bottom board comes to rest against the abutment surface; a second drive means operatively connected to the removable support means for removing support of the bottom board to allow the bottom board to fall by gravity onto a bottom board conveyor for movement from the separating station.
 2. The board separating device as defined in claim 1 wherein the removable support means includes a plurality of arms reciprocally mounted for generally horizontal movement between an extended position to receive the stack from the lateral conveying means and to slidably support the laterally moving stack and retracted position to permit the bottom board to fall by gravity to the bottom board conveyor.
 3. The board separating device as defined in claim 2 wherein the lateral conveying means includes a plurality of spaced endless chains having an upper flight for receiving the stack, moving the stack in the transverse path to a forward end of the upper flight opposing and spaced from the abutment surface and discharging the stack onto the arms when the arms are in the extended position and wherein said arms are positioned between the endless chains and project from the forward end of the upper flight to the abutment surface when the arms are in the extended position.
 4. The board separating device as defined in claim 2 wherein the second drive means includes: a common drive shaft extending transversely between the parallel arms; a plurality of rack gears affixed To the arms; a plurality of pinion gears affixed on the shaft in engagement with the rack gears; means operatively connected to the driveshaft for alternately rotating the shaft in opposite angular directions to move the arms between the extended position and the retracted position.
 5. The board separating device as defined in claim 1 further comprising a second bottom board conveyor positioned alongside the first bottom board conveyor and a deflector means intermediate the lateral path and the bottom board conveyors for selective directing the bottom board as it falls to one or the other bottom board conveyors. 